ORGANIC CARBON AND N-ALKANE DISTRIBUTION IN LATE CENOZOIC
SEDIMENTS OF ARCTIC GATEWAYS SITES 909 AND 911 AND THEIR
PALEOENVIRONMENTAL IMPLICATIONS: PRELIMINARY RESULTS

Rüdiger Stein and Rainer Stax

ABSTRACT

High northern latitude Sites 909 and 911 were drilled to gain information about the
development of paleoclimatic and paleoceanographic conditions of the North Atlantic region
during
late Cenozoic times. In the Miocene to Quaternary sediments, organic carbon values vary between
0.3% and about 2%. Organic geochemical investigations confirm the dominance of
terrestrial
organic matter in most of the samples. Flex rates or organic carbon are distinctly higher than those
observed in normal open-ocean environments. This is the result of the interplay between the warm
West Spitsbergen Current and the Arctic sea-ice cover. One of the main depositional processes is
the
melting of drift-ice masses, which releases high amounts of terrigenous siliciclastic and organic
particles. Changes in sea-ice cover also influence the surface-water productivity and, thus, the
marine
organic fraction of the sediment.

Date of initial receipt: 25 July 1995
Date of acceptance: 18 December 1995